1. Field of the Invention
The present invention relates to ski boot of the "rear entry" type, wherein the rear spoiler of the upper can be latched into a skiing position on the upper. More particularly, the invention is related to a control device for the flexion of the upper with respect to the lower shell.
2. Description of Background and Other Information
The aforementioned type of ski boot generally comprises a rear spoiler journalled on the lower shell in the zone corresponding to the heel, and latchable into the skiing position on the upper so as to maintain the lower leg of the skier, and closure means of the "cable-track" type, linking it to the front portion of the upper. In these boots, it is the front portion of the upper that enables the force and the amplitude of the flexion movements transferred to the upper and directed in the longitudinal axis of the boot to be controlled.
Therefore, when the upper is biased to flex, the front portion is displaced and/or is deformed by a certain amplitude in the direction of flexion, simultaneously driving the rear spoiler that then pivots on its journal located in the heel zone. Since this journal is offset towards the base with respect to the flexible zone and/or the deformable zone of the front portion of the upper, which extends to the level of the top of the foot and of the flexion fold of the leg of the skier, the result is a relative sliding between the rear spoiler and the front portion of the upper. This sliding is most substantial at the area of the upper edge of the upper and especially at the area of the edge of the rear spoiler in contact with the rear portion of the lower leg of the skier, due to the fact that it is the furthest portion of the rear spoiler from the journal of the latter. Since the sliding is produced when the closure means ensure close contact of the rear spoiler against the lower part of the leg, the skier experiences a rubbing sensation that can be more or less painful.
Moreover, such a concept of the upper of the boot does not enable the journal zones of the skier's ankle to be respected, as this is located at the level of the malleoli. Also, it can be noted that in this type of boot, the resistance of the upper in rearward flexion lacks firmness due to the fact that it is the front portion of the upper that alone controls the general flexion of the latter, and the fact that the closure means yet again amplify this lack of firmness.
This disadvantage is solved in other known rear entry ski boots, where the rear spoiler is equipped with nesting elements on its wings, that cooperate with the corresponding portions located on the sides of the upper, thus forming a latch that stops all relative movement of the rear spoiler with respect to the front portion of the upper in the longitudinal direction of the boot. However, due to this immobilization, the flexion possibility of the upper becomes very limited, even inadequate for satisfactory skiing practices, because the flexion possibilities of the ankle of the skier are limited too much.
Other rear entry ski boots are also known, including a type in which a rear spoiler is equipped with means that enable, on the other hand, relatively substantial frontward flexion, but no flexion at all towards the rear. The ski boot described in French Patent Application No. 2,358,119 is an example of this type of boot. As disclosed, it is by virtue of a segmentation of the rear spoiler that this spoiler is able to follow the lower part of the skier's leg during frontward flexion, and is able to retain the latter towards the rear from its initial position of closure of the upper, the rear spoiler behaving like "a lobster's tail". However, this type of boot has some of the disadvantages that have been described previously. Indeed, on the one hand, the relative sliding of the rear spoiler with respect to the rear portion of the lower leg of the skier during its flexion is not avoided because the segmentation of the rear spoiler is not centered on the pivot axis of the ankle, and on the other hand, the pivot axis of the upper does not respect that of the ankle of the skier. Also, due to the fact that the retention of the rear spoiler with respect to the front portion of the upper is basically done by means of closure means that link this front portion to the rear spoiler, the resistance of the upper in rearward flexion lacks firmness, and, at the very least, varies in accordance with the closure forces of the upper on the lower leg of the skier.